Base station controller

Base station controller

This application relates to wireless communication.

There are various types of wireless communication systems. For example, some wireless communication systems include General Packet Radio Service (GPRS), Global System for Mobile Communications Radio Access Network (GERAN), and Long Term Evolution (LTE) Evolved Universal Terrestrial Radio Access Network (EUTRAN).

When the mobile unit moves, it may need to switch from one network to another. Because not all networks are the same, a way to support switching between systems is useful.

A base station controller includes a receiver configured to receive wireless transmissions, a transmitter configured to transmit wireless signals, and a processor connected to the receiver and the transmitter and communicating with both the receiver and the transmitter. The processor is configured to initiate a handover (HO ) To control the transmitter to send a relocation (relocation) request, and receive a relocation command containing an evolved Node-B (eNB) identifier (ID) from the receiver.

The term "wireless transmit/receive unit (WTRU)" referred to below includes but is not limited to user equipment (UE), mobile station, fixed or mobile user unit, pager, cell phone, personal digital assistant (PDA), computer or Any other type of user equipment that can work in a wireless environment. The term "base station" referred to below includes but is not limited to Node-B, site controller, access point (AP), or any other type of peripheral equipment that can work in a wireless environment.

Figure 1 illustrates an example of a general network structure of the LTE system structure 100. The LTE system 100 illustrates the network interconnection (interworking) between the LTE system structure and the existing GERAN and UTRAN based on the GPRS core. The LTE system includes an evolved radio access network (RAN) (E-Node B) connected to an evolved packet core, and an internal AS anchor (anchor). The evolved packet core contains a mobility management entity/user plane entity ( MME/UPE). The evolved packet core is connected to HSS, PCRF, HSS, operator IP servers (such as IMS, PSS, etc.), non-3GPP IP access networks, and wireless local area network (WLAN) 3GPP IP access areas ( block). Operating IP servers (such as IMS, PSS, etc.) are also included in the LTE system 100. The GPRS core includes the Serving GPRS Support Node (SGSN), which is responsible for mobility management, access procedures, and user plane control. The GPRS core also contains the Gateway GPRS Support Node (GGSN), from where the network connects to external networks and other operator servers. The operator's IP services include the IP Multimedia Service Subsystem (IMS), which controls voice over IP (VoIP) and other multimedia services. Non-3GPP IP access includes connections to other technologies such as 3GPP2 (CDMA2000) and WiMAX (such as the IEEE802.16 system). The evolved core is also connected to a WLAN network, which is incorporated into 3GPP through a network interconnection structure defined by 3GPP.

Figure 2 illustrates an example of the first stage handover procedure 200 when the WTRU transfers from the coverage area of the GERAN system to the coverage area of the LTE system. As shown in Figure 2, the WTRU (marked with an oval at the bottom of the figure) is switching from one system to another. The WTRU is currently connected to the Gateway GPRS Support Node (GGSN) and the Target Base Station Controller (BSC) through the Serving GPRS Support Node (SGSN).

The location area/routing area (LA1/RA1) included in the cells belonging to the GERAN system is different from those belonging to the location area/routing area (LA2/RA2) of the LTE-based cells. In some configurations, although GERAN cells may overlap with LTE cells, these cells can maintain different LA/RA configurations due to the difference between the two system structures.

Figure 3 illustrates an example of the second phase handover procedure 300 from the GERAN system to the LTE system, which can be optionally used. When the WTRU switches from one system to another system, it can create a channel between the target BSC and the evolved NodeB. When a new connection is being established through the evolved core network, the channel temporarily forwards the currently waiting data between the GERAN system and the WTRU through the e Node-B. This should ensure that no data is lost during the transfer. The operator can choose not to perform this step and come to a complete transfer situation where no connection is established between the GERAN BSC and the eNode-B. Data forwarding can be generated at a higher layer between the two core networks.

Figure 4 illustrates an example of the third stage handover procedure 400 from the GPRS/GERAN system to the LTE system. As shown in Figure 4, the WTRU is currently connected to the access gateway (AGW) through the new MME and the target E-NodeB.

Figure 5 is a functional block diagram of the WTRU 510 and the base station 520. As shown in Figure 5, the WTRU 510 communicates with the base station 520, and both are configured to support handover from GPRS/GERAN to LTE EUTRAN.

In addition to the components that can be found in a typical WTRU, the WTRU 510 includes a processor 515, a receiver 516, a transmitter 517, and an antenna 518. The processor 515 is configured to support handover from GPRS/GERAN to LTE EUTRAN. The receiver 516 and the transmitter 517 communicate with the processor 515. The antenna 518 communicates with both the receiver 516 and the transmitter 517 to facilitate the transmission and reception of wireless data. The processor 515, receiver 516, transmitter 517, and antenna 518 may be configured as a GPRS/GERAN radio transceiver, or as an LTE EUTRAN radio transceiver. Also, although only one processor, receiver, transmitter, and antenna are shown, its worth noting that the WTRU 510 may include multiple processors, receivers, transmitters, and antennas, so different sets of processors, receivers, transmitters, etc. The receiver and antenna work in different modes (such as GPRS/GERAN transceiver or LTE EUTRAN transceiver).

In addition to the components that can be found in a typical base station, the base station 520 includes a processor 525, a receiver 526, a transmitter 527, and an antenna 528. The processor 525 is configured to support handover from GPRS/GERAN to LTE EUTRAN. The receiver 526 and the transmitter 527 communicate with the processor 525. The antenna 528 communicates with both the receiver 526 and the transmitter 527 to facilitate the transmission and reception of wireless data.

It should be noted that the WTRU 510 and the base station 520 can communicate with other network devices.

Figures 6A-6C illustrate examples of signal diagrams of the switching program 600. In the signal diagram of Figure 6A-6C, the dual-mode WTRU (LTE/GERAN) 510, the target e-Node B (T-ENB) 520, the serving BSC (S-BSC) 530, the LTE-MME 540, and the serving first Second-generation (2G) SGSN 550, and LTE UPE/gateway/GGSN 560. The WTRU 510 includes LTE and GERAN transceivers.

As shown in Figures 6A-6C, in the GERAN mode of the dual-mode WTRU 510 and between entities, user downlink (DL) and uplink (UL) traffic is generated. In step 601, measurements are performed at the WTRU 510. In one example, the measurement is performed by the GERAN transceiver in the WTRU 510 on the LTE network. Then, the WTRU 510 sends a measurement report (LTE) signal (602) to the S-BSC 530. The inter-system HO is started, and LTE is the target (step 603). The relocation request signal 604 contains the source cell ID and the target cell ID, and the signal is sent from the S-BSC 530 to the serving 2G SGSN 550. The serving 2G SGSN determines the target system ID and MME ID (step 605), and forwards the relocation request to the LTE-MME 540.

The LTE-MME 540 determines the target e-Node B ID, and if the target e-NodeB ID is not included in the signaling message 606, requests the user profile and context (step 607). The LTE-MME 540 sends a handover request signal (608) to the T-ENB 520, including the cell ID, MME ID, GGSN TEID, and International Mobile User Identity/Temporary Mobile User Identity (IMSI/TMSI). T-ENB 520 determines channel availability and initiates radio access bearer (RAB) establishment (step 609). T-ENB 520 sends handover request response ACK (including IMSI/TMSI) and signal (610) to LTE-MME 540, LTE-MME 540 sends relocation response signal 611, which includes IMSI and TE Node B for serving 2G SGSN 550 ID. Then, the LTE-MME 540 creates the MM state and the SM state to prepare to start the packet data protocol (PDP) context information (step 612).

The serving 2G SGSN 550 sends a relocation command signal (613), which includes the TMSI and the E-Node B ID to the S-BSC 530, and the S-BSC 530 establishes a temporary channel to the E-Node B to forward data (step 614). Then, the user information is forwarded between T-ENB 520 and S-BSC 530, and HO command 615 is sent from T-ENB 520 to the GERAN transceiver of WTRU 510, and the GERAN transceiver of WTRU 510 sends it to the LTE transceiver. Start/synchronize radio signal (616), which includes the target channel ID. The T-ENB 520 sends a relocation detection signal (617) to the LTE-MME 540, and the LTE transceiver acknowledges (ACK) (618) to start/synchronize the wireless signal.

Send the HO complete signal (619) from the GERAN transceiver to the S-BSC. Perform RAN information and RAB establishment (620) between the LTE transceiver and T-ENB 520, and user DL/UL traffic flows (flow). The PS additional signal is sent from the LTE transceiver (621) to the T-ENB 520, and the T-ENB 520 forwards the signal to the LTE-MME 540 (622). LTE-MME 540 sends PS additional acceptance signal (623) to LTE transceiver through T-ENB 520, T-ENB 520 responds with PS additional acceptance ACK (624), which is sent to LTE-MME through T-ENB 520 540.

The MME-LTE updates the PDP context with the new E-Node B TEID (step 625), and sends an update PDP context signal (626) to the LTE UPE/gateway/GGSN 560. In addition, user data can be sent together with the GPRS channel protocol user plane (GTP-U).

The HO completion signal (627) is sent from the LTE-MME 540 to the serving 2G SGSN 550, and the serving 2G SGSN 550 sends a release signal (628) to the S-BSC 530, and sends a HO completion ACK (629) to the LTE-MME 540. The LTE UPE/gateway/GGSN 560 switches the traffic from the SGSN to the E-NodeB (step 630), and the S-BSC 530 releases the E-NodeBBBS channel and stops forwarding data (step 631). A release ACK (632) is sent from the S-BSC 530 to the serving 2G SGSN 550, and user DL/UL data and control data are performed between the LTE transceiver T-ENB 520 and the LTE UPE/gateway/GGSN 560.

7A-7C illustrate an example of the signal diagram of the alternative switching program 700. As shown in Figures 7A-7C, in the GERAN mode of the dual-mode WTRU510 and between entities, user downlink (DL) and uplink (UL) traffic is generated. In step 701, measurement is performed at the WTRU 510. Then, the WTRU 510 sends a measurement report (LTE) signal (702) to the S-BSC 530. The inter-system HO is started, and LTE is the target (step 703). The relocation request signal 704 containing the source cell ID and the target cell ID is sent from the S-BSC 530 to the serving 2G SGSN 550. The serving 2G SGSN determines the target system ID and MMEID (step 705), and forwards the relocation request to the LTE-MME 540.

The LTE-MME 540 determines the target e-NodeBID, and requests the user profile and context if the target e-Node BID is not included in the signaling message 706 (step 707). LTE-MME 540 sends a handover request signal (708) to T-ENB 520. The handover request signal includes cell ID, MME ID, GGSN TEID and International Mobile User Identifier/Temporary Mobile User Identifier (IMSI/TMSI) . T-ENB5 20 determines channel availability and initiates radio access bearer (RAB) establishment (step 709). T-ENB 520 sends handover request ACK (including IMSI/TMSI) and signal (710) to LTE-MME 540. The LTE-MME 540 sends a relocation response signal 711. The relocation response signal 711 includes the information for the serving 2G SGSN 550. IMSI and TE Node B ID. Then, the LTE-MME 540 establishes the MM state and the SM state to prepare to activate the packet data protocol (PDP) context information (step 712).

The serving 2G SGSN 550 sends a relocation command signal (713), which includes the TMSI and the E-Node B ID to the S-BSC 530, and the S-BSC 530 establishes a temporary channel to the E-NodeB to forward data (step 714). Then, the user information is forwarded between T-ENB 520 and S-BSC 530, and HO command 715 is sent from T-ENB 520 to the GERAN transceiver of WTRU 510, and the GERAN transceiver of WTRU 510 sends it to the LTE transceiver. Activate/synchronize the wireless signal (716), which includes the target channel ID. The ACK is sent from the LTE transceiver (717), and the HO complete message (718) is sent from the GERAN transceiver to the S-BSC 530, and the S-BSC 530 forwards the HO complete signal (719) to the T-ENB 520. RAN and RAB establishment occurs between the LTE transceiver and T-ENB 520, and T-ENB 520 sends a relocation detection message (720) to LTE-MME 540.

Generate user DL/UL traffic between the LTE transceiver and T-ENB 520. The MME-LTE updates the PDP context with the new E-Node B TEID (step 721).

The HO complete signal (722) is sent from the LTE-MME 540 to the serving 2G SGSN 550, the serving 2G SGSN 550 sends a release signal (723) to the S-BSC 530, and the HO complete ACK (724) is sent to the LTE-MME 540. The LTE UPE/gateway/GGSN 560 switches the service from the SGSN to the E-Node B (step 725), and the S-BSC530 releases the E-Node B BBS channel and stops forwarding data (step 726). Send release ACK (727) from S-BSC 530 to serving 2G SGSN 550, as well as user DL/UL data and control data between LTE transceiver T-ENB 520 and L'TE UPE/gateway/GGSN 560 .

As described in Figure 1-7C above, before the source 3GPP access system instructs the WTRU 510 to switch to the target 3GPP access system, the target 3GPP access system has already prepared radio resources. In order to forward data when the core network resources are arranged, a channel (basic traffic setup (BSS) and E-Node B) is established between two radio access networks (RAN).

The control interface can exist in the core layer between the 2G/3G SGSN and the corresponding MME to change the mobility context and session context of the movement. In addition, the target system may provide instructions to the WTRU 510 regarding wireless access requirements, such as wireless resource configuration, target cell system information, and so on.

In order to avoid the loss of user data (such as by forwarding), there is an intermediate state during the switch from sending DL U-plane data from the source system to the target system before the U-plane is directly converted to the target system. You can also use bi-casting until the 3GPP anchor determines that it can directly send DL U-plane data to the target system.

Although the features and elements of the present invention are described in a specific combination in the preferred embodiment, each feature or element can be used alone without the other features and elements of the preferred embodiment, or It can be used in various situations with or without combining with other features and elements of the present invention. The method or flowchart provided by the present invention can be implemented in a computer program, software, or firmware executed by a general-purpose computer or processor, wherein the computer program, software, or firmware is included in a computer-readable storage in a tangible manner In the medium. Examples of computer-readable storage media include read-only memory (ROM), random access memory (RAM), scratchpads, cache memory, semiconductor storage devices, internal hard disks, and removable disks. Magnetic media, magneto-optical media, and optical media such as CD-ROM discs and digital versatile discs (DVD).

For example, suitable processors include: general-purpose processors, special-purpose processors, conventional processors, digital signal processors (DSP), multiple microprocessors, one or more microprocessors associated with the DSP core, Controller, microcontroller, dedicated integrated circuit (ASIC), field programmable gate array (FPGA) circuit, any kind of integrated circuit (IC) and/or state machine.

The processor associated with the software can be used to implement a radio frequency transceiver for use in a wireless transmit and receive unit (WTRU), user equipment (UE), terminal, base station, radio network controller (RNC), or any host Use it in your computer. WTRU can be used in combination with modules implemented in hardware and/or software, such as cameras, camera modules, video phones, speaker phones, vibration devices, speakers, microphones, TV transceivers, hands-free headsets, keyboards, Bluetooth<img file="TWM335897U_D0001.tif" />Module, frequency modulation (FM) wireless unit, liquid crystal display (LCD) display unit, organic light-emitting diode (OLED) display unit, digital music player, media player, video game console module, Internet browser And/or any wireless local area network (WLAN) module.

<p>100. . . LTE system</p><p>200, 300, 400. . . Switch program</p><p>510. WTRU. . . Wireless transmitting/receiving unit</p><p>515, 525. . . processor</p><p>516, 526. . . Receiver</p><p>517, 527. . . transmitter</p><p>518, 528. . . antenna</p><p>520. . . Base station, target e-Node B (T-ENB)</p><p>530. . . Service BSC (S-BSC)</p><p>540. . . LTE-MME</p><p>550. . . Serves the second generation (2G) SGSN</p><p>560. . . LTE UPE/Gateway/GGSN</p><p>602. . . Measurement report (LTE) signal</p><p>604. . . Relocation request signal</p><p>606. . . Signaling message</p><p>608. . . Handover request signal</p><p>610. . . Signal</p><p>611. . . Relocate the response signal</p><p>613. . . Relocation command signal</p><p>615. . . HO command</p><p>616. . . Start/synchronize radio signal</p><p>617. . . Relocate the heartbeat</p><p>618. . . LTE transceiver acknowledgement (ACK)</p><p>619. . . HO complete signal</p><p>620. . . RAN information and RAB establishment</p><p>621. . . PS additional signal</p><p>622. . . LTE-MME 540</p><p>623. . . PS additional receiving signal</p><p>624. . . PS additional accept ACK</p><p>626. . . Update PDP context signal</p><p>627. . . HO complete signal</p><p>628. . . Release signal</p><p>629. . . HO complete ACK</p><p>632. . . Release ACK</p><p>702. . . Measurement report (LTE) signal</p><p>704. . . Relocation request signal</p><p>706. . . Signaling message</p><p>708. . . Handover request signal</p><p>710. . . Signal</p><p>711. . . Relocate the response signal</p><p>713. . . Relocation command signal</p><p>715. . . HO command</p><p>716. . . Activate/synchronize wireless signal</p><p>717. . . ACK</p><p>718. . . HO complete message</p><p>719. . . HO complete signal</p><p>720. . . Relocate the detection message</p><p>722. . . HO complete signal</p><p>723. . . Release signal</p><p>724. . . HO complete ACK</p><p>727. . . Release ACK</p><p>UTRAN. . . Universal terrestrial radio access network</p><p>GERAN. . . Global System for Mobile Communications Radio Access Network</p><p>RAN. . . Evolved Radio Access Network</p><p>GPRS. . . General Packet Radio Service</p><p>MME. . . Mobility management entity</p><p>UPE. . . User plane entity</p><p>WLAN. . . Wireless local area network</p><p>GGSN. . . Gateway GPRS Support Node</p><p>SGSN. . . Serving GPRS Support Node</p><p>BSC. . . Target base station controller</p><p>LA1/RA1, LA2/RA2. . . Location area / routing area</p><p>AGW. . . Access gateway</p><p>LTE. . . Long-term evolution</p><p>IMSI. . . International Mobile User Identifier</p><p>TMSI. . . Temporary mobile user identifier</p><p>RAB. . . Radio access bearer</p>

The present utility model can be understood in more detail from the following descriptions, which are given in the form of embodiments and can be understood in conjunction with the accompanying drawings, in which:

Figure 1 illustrates an example of a general network structure of the LTE system structure;

Figure 2 illustrates an example of the first phase handover procedure from the GERAN system to the LTE system;

Figure 3 illustrates an example of the second phase handover procedure from the GERAN system to the LTE system;

Figure 4 illustrates an example of the third-stage handover procedure from the GPRS/GERAN system to the LTE system;

Figure 5 is a functional block diagram of the wireless transmitting/receiving unit and the base station;

Figures 6A-6C illustrate examples of signal diagrams for switching programs; and

Figures 7A-7C illustrate examples of signal diagrams for alternative switching programs.